Cellular distribution of Egr1 transcription in the male rat pituitary gland

Abstract

The transcription factor gene Egr1 is necessary for female fertility; EGR1 protein is an established molecular regulator of adult female gonadotroph function where it mediates GNRH-stimulated transcription of the Lhb gene. Recent studies have also implicated pituitary EGR1 in the mediation of other physiological signals indicating an integrative function. However, the role of EGR1 in males is less well defined and this uncertainty is compounded by the absence of cellular expression data in the male pituitary gland. The aim of this study, therefore, was to define the distribution of Egr1 gene expression in the adult male rat pituitary. To further this aim, we have evaluated cellular populations in a transgenic rat model (Egr1-d2EGFP), in which we demonstrate regulated green fluorescent protein (GFP) expression in EGR1C pituitary cells. Cellular filling by GFP enabled morphological and molecular differentiation of different populations of gonadotrophs; Egr1 transcription and LHB were highly co-localised in a major population of large cells but only minimally co-localised in small GFPC cells; the latter cells were shown to be largely (80%) composed of minority populations of GHC somatotrophs (9% of total GHC) and PRLC lactotrophs (3% of total PRLC). Egr1 transcription was not found in TSHC, ACTHC or SOX2C precursor cells and was only minimally co-localised in S-100bC folliculostellate cells. Our demonstration that the Egr1 gene is actively and selectively transcribed in a major sub-population of male LHBC cells indicates a largely conserved role in gonadotroph function and has provided a basis for further defining this role.

Genome-wide patterns of copy number variation in the Chinese yak genome

“…TSEG2 , AKR1C3 and IZUMO1 are sperm-specific expressed genes and have a role in spermatogenic cell development and fertility [ 55 – 57 ]. LHB is expressed in the pituitary gland and promotes spermatogenesis and ovulation; mutations in this gene are associated with polycystic ovary syndrome in women [ 58 ]. SPACA4 encoded protein is retained on the inner acrosomal membrane of spermatozoa and plays a role in sperm–egg binding and fertilization [ 59 ].…”

Contribution of TEX15 genetic variants to the risk of developing severe non-obstructive oligozoospermia

“…This SNP showed strong evidence of functionality, including high scoring by different functional impact prediction methods as well as an overlap with testis-specific active chromatin epigenetic marks. Interestingly, the sequence surrounding this SNP corresponds to a TFBS for different key transcription factors related with spermatogenesis, including EGR1 ( Tourtellotte et al, 2000 ; Man et al, 2014 ), CTCF ( Hernandez-Hernandez et al, 2016 ; Rivero-Hinojosa et al, 2021 ), SMC3 ( Eijpe et al, 2000 ; James et al, 2002 ), YY1 ( Wu et al, 2009 ; Kim et al, 2016 ), CCNT2 ( Teng et al, 2011 ), E2F6 ( Pohlers et al, 2005 ; Dahlet et al, 2021 ), and MAX ( Maeda et al, 2013 ), and it is annotated to be transcriptionally active in the testis ( Davis et al, 2018 ). Moreover, this SNP was predicted to modify the activity of E2F1, which has been associated with human SPGF ( Jorgez et al, 2015 ; Rocca et al, 2019 ).…”

Molecular phenotyping of transient postnatal tyrosine hydroxylase neurons in the rat bed nucleus of the stria terminalis

“…Transgene-derived GFP and a variety of endogenous antigens were detected by standard fluorescence immunohistochemistry using described procedures, and a number of primary antibodies, some of which have been validated in previous studies from this laboratory ( Table 1; Man et al, 2007;Hoefflin and Carter, 2014;Man et al, 2014). Antibodies used for the first time in this laboratory were validated firstly by confirming sub-cellular/brain region detection accuracy, and also through reference to previous use in peer-reviewed publications ( Table 1).…”